A customer accessing and executing a computer application on a shared server in a computer network may be charged for access to the application based on a flat rate or simple access time. Depending on how the application utilizes system resources, the billing method may or may not reflect actual usage of the system. An application utilizing a large percentage of system resources would cost the same as one utilizing only a small fraction. There exists a need for a usage billing method which bills according to actual usage of the computer system resources by an application.